Question 848951
Sum table
2 3 4 5 6 7
3 4 5 6 7 8
4 5 6 7 8 9
5 6 7 8 9 10
6 7 8 9 10 11
7 8 9 10 11 12

16)

P[die is 2 or sum is 6 or 7]  = P[1st die is 2] + p[sum is 6 or 7] - p[2 and sum is 6 or 7]

(2,4) (2,5) satisfy both conditions so P[first is 2 and sum is 6 or 7] = 2/36 

P[sum is 6 or 7] = 13/36

1/6 + 13/36  - 2/36 ={{{highlight(17/36)}}}

17)

P[sum is 11] = 2/36
P[2nd die is 5] = 1/6
P[sum is 11 and 2nd die is 5] = 1/36   (5,6)

2/36 + 1/6 - 1/36 = {{{highlight(7/36)}}}